Explore Scientific Nebula Filter CLS 2" Light Pollution Filter for City Light Suppression Useful where you do not have a dark-sky site Observe deep-sky objects from brighter areas Increase contrast of deep-sky objects Range: 436 nm to 536 nm; peaks at 488 nm 98.3% Transmission Fits 2" Eyepieces This is a general-purpose light-pollution reduction filter which fits into your 2" eyepieces that have internal (female) filter threads. The Explore Scientific Nebula City Light Suppression (CLS) Filter 2" is designed for observing a broad range of deep sky objects including nebulae and galaxies. The Nebula Filter CLS 2" from Explore Scientific does a good job of increasing contrast, providing a darker sky background. It does this by filtering out the wavelengths of light commonly found in municipal-based (City lights) light pollution, while allowing the light from nebulae and galaxies to pass through so you can see them better. It has a total transmission specification of 98.3%.
